The Go Playground is a web service that runs on
golang.org's servers.
The service receives a Go program, compiles, links, and
runs the program inside a sandbox, then returns the output.

There are limitations to the programs that can be run in the playground:

The playground can use most of the standard library, with some exceptions.
The only communication a playground program has to the outside world
is by writing to standard output and standard error.

In the playground the time begins at 2009-11-10 23:00:00 UTC
(determining the significance of this date is an exercise for the reader).
This makes it easier to cache programs by giving them deterministic output.

The playground uses the latest stable release of Go.
To find the precise version, run this program.

The playground service is used by more than just the official Go project
(Go by Example is one other instance)
and we are happy for you to use it on your own site.
All we ask is that you contact us first,
use a unique user agent in your requests (so we can identify you),
and that your service is of benefit to the Go community.